The present invention relates generally to a communications cable terminal block, and, more particularly, to a communications cable terminal block switching mechanism that allows a wire pair to be expressed through, in effect bypassing the terminal block, or to be terminated to a service wire at the block.
Terminal blocks are typically used in the telecommunications industry to connect multiple wire pairs, for example, to connect telephone service wires to telephone company distribution cables. Such terminal blocks typically connect from 2 to 50 individual service wire pairs to the distribution cable which may have several thousand wire pairs. Generally, the terminal block is spliced to the distribution cable through a splicing cable or stub cable which forms part of the terminal block. The customer service wires are then connected to the terminal blocks through some type of terminal which, ideally, enables the service wires to be easily connected, disconnected and reconnected on site.
A number of approaches to connect the service wire pairs to the terminal block have been described in U.S. Pat. No. 5,149,278 (Waas et al.). The ""278 patent describes one technique in which a stripped service wire is connected to a binding post and secured with a cap. Another technique noted in the ""278 patent is the use of an insulation displacement contact terminal in which the insulation is severed by a blade as the service wire is secured to the terminal. The blade then also acts as the contact connecting the service wire conductor to the cable. In this case, the service wire is also further secured by a cap.
However, each of the approaches in the ""278 patent address only the need for an easy method of connecting a service wire to a terminal block. These techniques do not address the potential need to take a distribution cable pair that has been connected to a service wire at the terminal block, and easily disconnect the cable pair from the service wire and reconnect the cable pair to the downstream distribution cable. In each of the approaches discussed in the ""278 patent, for example, once the distribution cable pair has been connected to a service wire at the terminal block, in order for that pair to be disconnected from the service wire and xe2x80x9creconnectedxe2x80x9d to the downstream distribution cable, the pair would need to be removed from the terminal block and re-spliced to the downstream cable. This is both time consuming and likely to require re-opening the original splice, resulting in greater likelihood of potentially harmful exposure of the final splice to the outside environment.
The present invention is therefore directed to the problem of developing a controlled distribution communications cable terminal block in which a mechanism is provided that allows a wire pair of a telephone company distribution cable to easily switch between two conditions, the first condition having the wire pair terminated to a service wire at a terminal block, and the second condition having the wire pair express through without termination, or xe2x80x9cbypassxe2x80x9d, the terminal block.
The present invention solves these problems by implementing a communications cable terminal block switching mechanism in a terminal block housing with a number of chambers and a number of openings for service wires to be inserted into the chambers. Based on the condition of the switching mechanism, a wire pair may be expressed through the terminal block unterminated, or, a wire pair may be terminated to a service wire at the block.
More specifically, the switching mechanism of the present invention provides a number of sets of electrical contact elements, corresponding to the number of openings in the block. Each of the sets of contact elements is configured in one of each of the chambers. An actuator mechanism is coupled to one of the chambers and is adapted to move components within the chamber such that electrical connections between a wire inserted into the chamber and the corresponding set of electrical contact elements are altered based on movement of the actuator mechanism.
According to one aspect of the present invention, each of the chambers has a base, into which a set of the electrical contact elements is inserted, a chamber housing, attached to the base, having an opening for the actuator mechanism and a molded body, inside the chamber housing, having an external threaded portion.
In another aspect of the present invention, the actuator mechanism is a cap, having an outer portion extending outside of the terminal block housing, and an inner threaded portion extending into the chamber housing, aligning with the external threaded portion of the molded body in the chamber.
In one particular embodiment of the present invention, rotating the cap causes the body of the chamber to move perpendicularly to a plane of the base and the plane of rotation of the cap.
In yet another aspect of the present invention, each set of electrical contact elements includes an incoming element, an outgoing element, a drop wire element and a bridging element. The incoming, outgoing and drop wire elements are each inserted into the base of the chamber, and the bridging element is inserted into the body of the chamber. The bridging element is adapted to move, in accordance with movement of the actuator mechanism, between first and second positions, in each of which different electrical contact elements are electrically connected, thereby providing a controlled distribution terminal block with switching mechanism which enables service wires to be easily connected, disconnected and reconnected on site.